This invention relates to hepatitis A (infectious hepatitis) antigen and to a method for its preparation, to its use in an assay for hepatitis A, and for the preparation of hepatitis A vaccine.
Hepatitis A is a liver disease which, while not commonly fatal, can involve many weeks of debilitating illness. It is usually spread by direct contact with an infected individual or by contaminated drinking water or food. Studies of hepatitis A have been hampered by the lack of a simple specific assay for antibody against hepatitis A virus. The development of such an assay has not heretofore been possible because no preparations have previously been available which contain hepatitis A antigen in such quantities as to enable the performance of complement fixation, immune adherence or other serologic assays. The only assays previously available were neutralization testing in marmosets (Provost et al., Proc. Soc. Exp. Biol. Med., 142, 1257, 1973) and immune electron microscopy (Feinstone et al., Science, 8 Nov. 1973) with fecal extracts. These methods were cumbersome, expensive and not applicable to routine testing.
It is, accordingly, an object of the present invention to provide a practical method for obtaining hepatitis A antigen. Another object is to provide hepatitis A antigen in sufficient quantities for use in an assay for hepatitis A. A further object is to provide a vaccine for hepatitis A. These and other objects of the present invention will be apparent from the following description.